GB2085068A

GB2085068A - Ball and socket joints

Info

Publication number: GB2085068A
Application number: GB8130905A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-10-14
Filing date: 1981-10-13
Publication date: 1982-04-21
Also published as: IT1144799B; IT8168325A0; SE8007174L; DE3140758A1

Abstract

A coupling is adapted for pivotable connection of two components (20,22) having a seat (21) and a ball (23) respectively. The ball is adapted to be received in the seat while a throat portion (25) connected to the ball may be received within a slot (24) having a width slightly greater than the throat portion (25) but smaller than the diameter of the ball. An opening allowing introduction of the ball (23) into the seat is continuously open and support or stop means (34) are adapted to avoid accidental release of the coupling due to passage of the ball out of the seat until such time as the members are pivoted relative to each other to such a position that said stop means no longer can prevent release of the coupling. <IMAGE>

Description

SPECIFICATION A coupling Technical field and prior art This invention is related to a coupling for pivotable and releasable interconnection of two members, one of said members being provided with a iink head carried by a shaft while the other of said members is provided with a seat for accommodating said head, which during relative movement of the members is in movement within the seat, said head being insertable into the seat through an opening merging into a slot having a width allowing reception of a portion of the shaft but not the head.

Although this coupling may be used within other technical fields, a preferred use is for connecting the steering element of a water craft, e.g. the rudder of a sailing boat, to an extension arm, via which the helmsman may impose steering movements to the rudder, or means for securing the rudder in a desired rudder angle.

A coupling of the kind defined hereinabove is disclosed in the Swedish patent specification 202 474, said coupling having the seat provided in a core portion, which is surrounded by a sleeve rotatably journalled about said core portion. The slot for receiving a portion of the shaft carrying the head is provided in the sleeve as is the opening making it possible to introduce the head into the seat. A spring is adapted to rotate the sleeve to a locking position relative to the seat in the core portion, i.e. a position in which the slot is located opposite the seat. A severe disadvantage with this previous coupling is that it is relatively expensive in that it comprises the rotatable parts just mentioned; another severe disadvantage being that the coupling is relatively unsafe in that failure of the spring operating the sleeve may cause accidental disengagement of the coupling.

Brief Disclosure of the Invention The invention aims at eliminating those disadvantages connected to the previous coupling.

This is obtained by the features defined in the characterizing portion of claim 1. These features result in a very simple non-expensive coupling which nevertheless is quite safe since it does not rely on parts movable by springs and since the stop means prevent accidental disengagement of the coupling within that field of relative movements between the members being of interest in connection with rudder control means etc.

Brief Description of the Drawings An embodiment according to the invention will be described hereinafter with reference to the appended drawings, in which Fig. 1 is a side view of a rudder holder including a coupling according to the invention; Fig. 2 is a side view in a greater scale of the coupling in Fig. 1; Fig. 3 is a plan view along the line 3-3 of the coupling according to Fig. 2; Fig. 4 is an end view in the direction 4-4 of the coupling illustrated in Fig. 2; Fig. 5 is a section along the line 5-5 in Fig. 3, the ball head being removed; Fig. 6 is a view similar to Fig. 3, the ball head being removed; Fig. 7 is a similar view as Fig. 2 but illustrating the members in another relative position; and Fig. 8 is an end view of an attachment for the rudder holder in Fig. 1.

Specific Disclosure of a Preferred Embodiment In Fig. 1 , the invention is illustrated as applied to a device for securing a boat rudder in a desired position. The steering element for the rudder is in this case an ordinary tiller 10, which is secured by a rod 11 which in this case is designed as a boat hook. The boat hook is at the right end thereof connected to the tiller via a coupling 12 according to the invention. The other end of the boat hook 11 is provided with a hook 12 and a point 13 terminating in a ball 14. Said ball is releasably secured in a slotted attachment 1 5 secured to the boat at any convenient loation.The boat hook 11 has an adjustable length and comprises in this case two telescopically associated elements 1 6 and 17, which are securable in any relative position of displacement by a locking device 18, which may be designed as comprising a sleeve 1 8 threadedly engaging the element 1 7 and adapted to press the end portion thereof onto the other element.

The coupling 12 (Figs. 2-7) according to the invention comprises two members, one 20 of which is provided with a seat and the other 22 of which is provided with a hinge head 23. The coupling is basically designed as a ball and socket joint so that the ball shaped head 23 is adapted to, in operation, be retained in the seat 21. In the embodiment illustrated, the member 20 comprising the seat 21 is adapted to be attached to the element 1 7 of the boat hook in any arbitrary manner. In a similar way, the member 22 comprising the ball 23 is adapted to be attached to the tiller 10 in any arbitrary manner such as by screwing or press fitting in a hole in the tiller etc.

However, the invention also comprises such embodiments in which the members forming the coupling 1 2 are shaped in one piece with the components 1 7 and 10 just mentioned or any other components intended to be pivotable relative to each other by means of the coupling.

As can be seen from Fig. 6, the member 20 has two flanges 28 projecting in a spaced relationship from the member in the longitudinal direction thereof. The seat 21 is defined by recesses in the inner sides of the flanges 28. The seat has an opening 26 extending transversally to the longitudinal direction of the member and allowing introduction and withdrawal of the ball 23 included in the member 22. The seat is generally cylindrical except as far as the bottom 29 thereof is concerned. As can be seen from Fig. 5, the bottom 29 of the seat may be formed by spherical surfaces. Those portions on the inner side of the flanges 28 that are not recessed to form the seat 21 form opposite ridges 31, which between themselves define a slot 24 slightly wider than the throat portion 25 beneath the ball 23 so that said throat portion may be received within and moved along the slot.The slot 24 is narrower than the diameter of the ball 23. Thus, the portions defining the slot 24 form a locking means preventing removal of the ball from the seat in any other way than through the opening 26. When the ball 23 is inserted into the seat 21, the members 20 and 22 are pivotable relative to each other in a plane coinciding with the longitudinal directions of the members about the joint formed by the ball and the socket, the throat portion 25 moving within the slot 24 during such pivotal movement. The slot 24 is open all the way from the bottom 29 up to the portion 33 adjacent to the opening to the seat 21. Thus, the opening 26 and the slot portion 33 form in unison an aperture allowing removal of the member 22 with the ball 23 when the members have been located in the relative position illustrated in Fig. 7.It is to be noted that the ridges 31 defining the slot 24 are curved so as to make certain that the throat portion 25 can move in the slot 24 in an unobstructed manner about the pivot center formed by the ball and the seat between the positions illustrated in Fig. 2 and Fig. 7.

As is apparent from Fig. 2, the slot 24 is designed in such a manner that the throat portion 25 can be moved therein to at least such a position that the throat portion is located opposite to the opening 26 for the ball. Preferably, the angle between the members 20 and 22 can be made even smaller than the one illustrated.

The member 22 that comprises the ball 23 is under the ball 23 and the throat portion 25 provided with a collar 34 forming a support or stop means for the member 20 in the position illustrated in Fig. 2. In said position, it is impossible to accidentally disengage the coupling by tending to move the member 20 upwardly or downwardly. In order to make it possible to release the members from each other, they must be pivoted to the position illustrated in Fig. 7 in which the stop means 34, which has the character of a nut thereby also serving for attaching member 22, is located generally in a plane coinciding with the longitudinal direction of the seat. However, pivotal movement to the position illustrated in Fig. 7 is not anything that would happen accidentally within the field of use contemplated by the present invention. In the position according to Fig. 7, the member 20 is moved in the direction indicated by arrow 27 in order to release the coupling.

Instead of providing the stop means 34 in the form of a collar or the like having a width greater than the width of the slot 24, it would per se be possible to provide the ball 23 in such a position relative to a tiller 10 or the like that a face or portion of such tiller forms the stop means.

Claims

1. A coupling for pivotable and releasable interconnection of two members, one of said members being provided with a link head carried by a shaft while the other of said members is provided with a seat for accommodating said head, which during relative movement of the members is in movement within the seat, said head being insertable into the seat through an opening merging into a slot having a width allowing reception of a portion of the shaft but not the head, characterized in that said opening and slot are arranged stationary relative to the seat and that the member comprising the head includes at least one stop means adapted to prevent, when the head is located in the seat and the shaft of the head is introduced into the slot, accidental disengagement of the coupling due to displacement of the head out of the seat.

2. A coupling according to claim 1, wherein the head comprises a ball.

3. A coupling according to claim 1 and 2, wherein the slot is designed to allow, with the head located in the seat, movement of the shaft in the slot into a position, wherein the shaft extends away from the head generally in the same direction, in which the head is insertable into the seat.

4. A coupling according to any previous claim, wherein said second member comprises two flanges projecting therefrom, said flanges forming said seat and slot between each other.

5. A coupling according to claim 4, wherein the flanges project in the longitudinal direction of the second member, the seat being located so as to allow introduction of the head into the seat transversally relative to said member.

6. A coupling according to any previous claim, wherein said stop means comprises an enlargement on the shaft spaced from the head, said enlargement having dimensions preventing passage thereof through the slot.

7. A coupling according to any of claims 1-6, wherein said stop means comprises a portion of the member carryiny the head.

8. A coupling according to any previous claim, wherein one of the members includes a steering element for water craft while the other of the members farms extension or securing means for the steering element.

9. A coupling according to claim 8, wherein the extension or securing means is designed as a boat hook.

10. A coupling according to claim 8 or 9, wherein the extension or securing means comprises means for varying the length thereof and means for attaching the end thereof located spaced from the steering element to the water craft.

11. A coupling constructed and arranged substantially as described herein with reference to the accompanying drawings.